Steam-engine.



No. 729,567. PATENIED JUNE 2,-1903. N. PRANQOIS, I

STEAM ENGINE.

APPLIOATION TILED JAN. 20, 1903.

N0 MODEL. 2 SHEETS-SHEET 1..

YKE NQFRI5 PETERS D P c Afro RN sys No. 729,667. PATENTED JUNE 2, 1903.

I N. PBANQOIS.

,. STEAM ENGINE.

I APPLICATION FILED JAN. 20. 1903. N0 MODEL, 2 SHEETS-SHEET 2.

line R S, Fig. 1.

Patented June 2, 1903.

i PATENT OFFICE.

NICOLAS FRANQOIS, OF JEMEPPE-SUR-MEUSE, BELGIUM.

STEAM- E NG-INE.

SPECIFICATION forming part of Letters Patent N 0. 729,567, dated June 1903- Application filed January 20,1903. Serial No. 139,853. (No model.)

5 gium, haveinvented certain new and useful Improvements in Steam-Engines,of which the following is a specification.

This invention relates to a special construction of cylinder for steam-engines, and more '10 particularly for engines working with high initial pressures and great expansion, the essential object of the invention being to secure simple and effective means for the steaminlet, allowing to dispense with the use of I 5 special inlet-valves.

Referring to the annexed drawings, Figure 1 is a vertical longitudinal section of a cylinder constructed according to my invention. Fig. 2 is a transverse section taken on Fig. 3 is a transverse seetion taken on line T U, Fig. 1.

In the drawings, A is an outer cylinder, 'in which are introduced two cylinders B and 0, provided each with a jacket B and G, ad-

justing and fitting tightly against the ends a of cylinder A. Each cylinder B O is closed at one end by a cover B 0 the two adjacent ends being open and leaving between them a space I in constant communication with the 0 outer cylinder A, in which the cylinders B O are supported on studs b c. In each cylinder B O is placed a hollow piston D E. The said pistons are rigidly connected through a tie-rod F and are keyed on apiston-rod G,

passing through the cover 0 in a suitable:

stuffing-box.

At the ends of the cylinders B vided with a port M L, formed in such a mannor as to allow a free passage to the steam from one face of the pistons D E to the other face when said pistons are at the end of their stroke near the covers B C The said ports M L may be obtained, for instance, by giving to the cylinders B O a greater diameter than the normal one at the ends and on a part of their inside periphery, said part being in longitudinal dimension somewhat longer than the rims D E of the pistons D E. The

outer ends each with a suitable steam-outlet valve P of any suitable construction.

The above-described arrangementof steamcylinder acts as follows: Steam is admitted in the outer cylinder A by any suitable opening-'forinstancathrough aninlet-openingK. The said steam fills the cylinder A, the space comprised between the cylinders B and O, and the corresponding jackets B and O, and also the space comprised between the two pistons D E. The said pistons being in the posit-ion shown in Fig. 1, steam is admitted to pass through the inlet-port M, as shown by the arrow, and to act on the back face of the piston D, causing consequently the two pistons to be moved simultaneously-forward. As soon as the inner edge d of piston D has re-covered the inlet-port M the steam-inlet is cut off and the expansion takes place. At the end of the forward movement of the pistons D E piston ,E covers the steam-inlet L, and as soon. as its inner edge 6 has passed the edge of the inlet-port the steam is allowed to pass from the space comprised between the two pistons to the back face of piston E. At this moment the outlet-valve P is acted upon at the other end of the engine, and the pistons begin a new or back stroke. It will be seen consequently that the piston D moves between H and I and piston E between I and J, and inversely.

According to the above construction each cylinder B O is adapted to expand freely under the action of heat. Further, the admission has the same value as the lineal lead,

' I the admissions are short, and consequently and 0, near. the covers 13 C each cylinder B O is -prowell adapted for great expansions. It will be observed that the steam acts only on the opposite faces of the pistons. The strain of the steam upon the inner face of one of the pistons is balanced by the action of. the steam on the opposite and inner face of the second piston. Y

The construction according to the invention has, further, the advatage to secure large reheating-surfaces for the steam, which is an important feature for the use of great expansions.

The engine may obviously be controlled or governed in any suitable manner-for in- I00 50 cylinders B O are further provided at their stance, by reducing or controlling the admission of the steam through the inletopening K or by controlling the outlet in a wellknown manner, so as to vary the power of the engine through the compression.

Having thus described my invention, I

claim 1. A cylinder A, two cylinders B C arranged in the first cylinder A, covers B O closing, the cylinders B C at the outer ends, two pistons D E rigidly connected together and movingin said cylinders B C, means for introducing steam between said pistons, means for causing the passage of the steam from between the pistons alternately to each end of the cylinders B 0 when the pistons are at the end of their stroke and outletvalves for the escape of the steam after its action on the outer faces of the pistons, there being ports in the ends of the cylinder and the pistons forming the valves, substantially as and for the purpose described.

2. A cylinder A, two cylinders B C arranged in the said cylinder A and leaving between them at the inner ends aspace communicating with the outer cylinder A, covers closing said cylinders B C at the outer ends, two pistons rigidly connected to each other moving together in said cylinders B O and leaving between them a space adapted to be filled with working steam, the cylinders B Cbeing provided near the covers with ports formed by giving to the cylinders a greater diameter than the normal one on a part of their inside periphery, said part being somewhat longer than the rim of the pistons D E, in order to allow the passage of the steam from the space between the pistons to the ends of the cylinders B G when the pistons are at the ends of their stroke, substantially as described and for the purpose set forth.

In witness whereof I have hereunto set my hand in presence of two witnesses.

NICOLAS FRANCOIS. \Vitnesses:

HUGH SAVAGE, SIMON PETRE. 

